- Статьи
- Science and technology
- Membrane field: scientists have found a new way of environmentally friendly water purification
Membrane field: scientists have found a new way of environmentally friendly water purification
Chemists from St. Petersburg, together with Chinese colleagues, have proposed a more environmentally friendly alternative to existing water purification systems — membranes based on cellulose derivatives. They are planned to be used for industry, but the technology itself is universal. With the help of the development, it is possible to purify both domestic and drinking water. An important advantage of the technology is that the membranes are biodegradable, which reduces the burden on ecosystems. However, it is too early to talk about industrial applications and the transition to a new generation of filters before industrial testing, experts interviewed by Izvestia said.
Which membranes are used for water purification
Chemists from St. Petersburg State University, together with colleagues from Tianjin University (China), have created effective and environmentally friendly ultrafiltration membranes for water treatment based on cellulose derivatives. As the developers explained to Izvestia, today petroleum-based polymers such as polysulfone, polyethersulfone, polyamides and polyvinylidene fluoride are used as membranes for water purification.
These materials have good mechanical properties and cope with their task, but their use is associated with serious environmental risks and leads to the dependence of manufacturers of such filters on petrochemical raw materials. In addition, the production of such materials leaves a significant carbon footprint, and waste disposal leads to the production of toxic substances and the formation of microplastics, which can accumulate in water and soil.
— Our research group has developed ultrafiltration membranes from a composition of cellulose acetate and nitrate, specially designed for the separation of protein solutions. The principle of operation is based on the ultrafiltration method, a process of membrane separation under pressure based on the sieve principle. That is, small particles pass through the filter, and large pollutants remain on it," said Anastasia Penkova, the author of the study, professor of the Department of Analytical Chemistry at St. Petersburg State University.
According to her, to create the membranes, the scientists used a method in which a prepared polymer solution is applied to a non-woven substrate, forming a thin homogeneous layer, which is then placed in a coagulation bath. At the final stage, chemists applied machine learning methods to optimize the composition and improve their transport characteristics.
The membranes will be used for industry, but the technology itself is universal. With the help of the development, it is possible to purify both domestic and drinking water, the university's press service said. This study is the first experience of using cellulose nitrate to create ultrafiltration membranes designed to separate proteins. To fully assess their effectiveness, it is planned to continue work on scaling the technology and studying their long-term stability.
Advantages of the new technology
The key advantages of the new technology can already be identified: the use of renewable raw materials, partial biodegradability, which reduces the burden on ecosystems, as well as lower cost compared to synthetic analogues, the scientists said. In addition, the innovative membranes demonstrate record-breaking performance in protein filtration while maintaining their filtering properties. Thus, with similar retention and antifouling properties, the new membranes have demonstrated more than 1.5 times higher performance compared to cellulose acetate analogues presented in the scientific literature.
Making filters from renewable materials is an important area of research, Vladimir Pinaev, a member of the Public Council under the Ministry of Natural Resources and Environment of Russia, editor—in-chief of the online magazine Waste and Resources, told Izvestia.
— At the same time, cellulose derivatives are used as a filter in this case. It is important to take into account the environmental impact of their production, including on an industrial scale. The question arises if the technology is used for protein solutions, how successfully it can be used for water filtration and what quality it will be after filtration. It's too early to talk about industrial applications and the transition to a new generation of filters before industrial testing," the expert said.
It is important to develop a new cleaning method in different conditions and with different pollutants. The recycling processes of new filters and their entire life cycle are also considered separately, said Irina Golovacheva, Deputy director of the RUDN University Institute of Ecology, member of the Public Council of the basic organization of the CIS member states for environmental education.
— The economic assessment of the process will depend on the efficiency and quality of the water after purification. If additional actions are not needed, then this is considered an advantage of the method. The permeability of filters (the volume of water that can be cleaned by a specific filter surface) and their service life will be the first arguments in favor of industrial—scale use, she noted.
The results of the study, supported by a grant from the Russian National Science Foundation, are published in the scientific journal Carbohydrate Polymers.
Переведено сервисом «Яндекс Переводчик»
